PDR TECHNIQUE / OPTICAL ASSESSMENT
Reading the reflection.
The reflection is your map.
A dent is easier to understand when its surface changes are made visible. PDR reflection reading is an observation skill, not an automatic indication of where to push.
Why a reflection board works
A straight or smoothly graded reflection becomes visibly distorted when the surface normal changes across a dent. A low, a surrounding crown and an unintended high can create different transitions in the viewed pattern. Apparent line movement must be interpreted with the angle of view and illumination in mind; reflections do not directly measure depth in millimetres.
Keep the panel fixed while you inspect
The dent does not travel around the door as the light or viewing angle moves. A controlled sweep of the board changes the reflected pattern across one stationary defect. This simple distinction matters in both practical inspection and educational animation: the apparent change is in what the observer sees, not in the location of the damage.
Map the low and the surrounding load
The centre of the visible depression is only part of the story. A sharply held feature line, edge return or internal brace changes surrounding tension and what force will do next. Pushing the deepest point first without understanding the crown can exchange one obvious dent for a cluster of high spots. Observation precedes tool selection.
A cycle of small moves and checks
During competent repair work, a technician repeatedly checks the reflection under useful lighting, applies a measured adjustment, and re-checks the whole affected region. Useful quality control includes looking from more than one angle, recognising micro-highs and deciding when further effort risks damage. A visually flatter line is not necessarily a safe reason to continue.
Limits and training
The optics help with cosmetic geometry; they do not identify hidden electrical equipment, structural reinforcement or damaged paint adhesion. Reflection training belongs alongside safe access planning, material understanding and supervised workshop practice. InspectaDent’s learning series explains why knowledge builds confidence without pretending videos confer competence.
EXPLORE FURTHER
See the bigger picture.
Related references and contact routes from InspectaDent.
Complete PDR guide → PDR learning series → Technical reference →INSPECTADENT · KENT, ENGLAND